Automatic primer valve for drain traps



g- 1, 1957 R. N. SULLIVAN 3,333,597

AUTOMATIC PRIMER VALVE FOR DRAIN TRAPS Filed Nov. 5, 1964 INVENTOR.

RICHARD N. SULLWAN United States Patent 3,333,597 AUTOMATIC PRllVIERVALVE FOR DRAIN TRAPS Richard N. Sullivan, 1843 SE. 60th Ave., Portland,Oreg. 97215 Filed Nov. 5, 1964, Ser. No. 409,173 8 Claims. (Cl. 137-102)This invention relates to a valve for supplying a small amount of waterperiodically to a drain trap.

When a drain is used infrequently, the water in its trap evaporatesallowing sewer gas to enter the building. It is, therefore, necessary toprovide an automatic device for supplying water periodically to thedrain trap to keep it filled. Various types of primer valves haveheretofore been developed and used for this purpose but all of them aresubject to one or more objections.

Two of the main objections to conventional primer valves are the use ofmetal springs and the requirement that they be installed directly in asupply pipe. Metal springs are objectionable because they must beadjusted to a particular water pressure and because they lose theirresilience in time. Variations in pressure in the supply main renderthem inoperative. A primer valve in a sup ply pipe is objectionablebecause in many buildings the supply pipe is remote to some of thedrains which must be primed. Other objections to conventional primervalves are their complex construction, high cost and general lack ofreliability over a long period of time.

The general object of the present invention is, therefore, to provide anautomatic primer valve which overcomes the above-mentioned objections.Particular objects are to provide a primer valve without springs or atleast without a calibrated spring, to provide a primer valve which isnot connected in the flow of a water supply line, to provide a primervalve which may be connected to a small branch line, to provide a primervalve which is self-compensating for changes in main pressure and toprovide a primer valve which is relatively simple and inexpensive tomanufacture but which is durable and reliable in operation. 7

In certain preferred embodiments the present primer valve is actuated bythe spring action of a pocket of compressed air. The air is compressedby the normal water pressure and when the water pressure is reduced, asby the opening of a faucet, the expansion of the air releases a smallquantity of water suificient to rebalance the air pressure against thereduced water pressure. A modification shows a spring substituted forthe air pressure but the arrangement is such that the spring does nothave to be calibrated.

The foregoing and other objects and advantages will become apparent andthe invention will be better understood from the following descriptionof the preferred embodiments illustrated on the accompanying drawing.Various changes may be made, however, in the details of construction andarrangement of parts and certain features may be used without others.All such modifications within the scope of the appended claims areincluded in the invention.

In the drawing:

FIGURE 1 is a sectional view of a primer valve embodying the features ofthe invention, the valve being in closed position;

FIGURE 2 is a fragmentary view similar to FIGURE 1, showing the valve inopen position;

FIGURE 3 is a view similar to FIGURE 2, showing a modification;

FIGURE 4 is a view showing the valve installed in a typical plumbingsystem;

FIGURE 5 is a fragmentary view of another modification; and

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FIGURE 6 is a fragmentary view of still another modification.

FIGURE 4 illustrates why a primer valve is necessary. The floor drain 10is connected through a drain trap 11 and drain pipe 12 with a sewer pipe13. If the water evaporates from trap 11, sewer gas can enter thebuilding. Drying of the trap 11 is prevented by the primer valve 15which supplies water periodically through a pipe 16. The primer valve issupplied by a small branch pipe 17 connected to a water supply pipe 18leading to the faucet 20. In this installation, the drain is relativelyclose to the supply pipe 18 but, in many cases, the nearest supply pipemay be quite remote.

Whenever a faucet or other valve is opened anywhere in the building,there is a drop in pressure in branch pipe 17 and this drop in pressure,however small, is utilized to actuate the primer valve 15 to release asmall amount of water through pipe 16 to the trap 11. One of theadvantages of the present primer valve is that it may be locatedanywhere between the supply pipe 18 and trap 11, and the connectingpipes 16 and 17 may be of relatively small size since the flowthroughthese pipes is negligible in relation to the flow through pipe 18when water is being used for normal purposes.

Referring now to FIGURE 1, the primer valve 15 is incorporated in ahollow body 25 having a flexible diaphragm 26 which forms an upper orsupply chamber 27 and a lower or dispensing chamber 28. For conveniencein manufacture, the periphery of the diaphragm is secured -to a capmember 29 having a recess which forms the chamber 27. Branch pipe 17 isconnected with cap 29 and communicates with chamber 27 through a screen30.

The center of the diaphragm is apertured to receive a short tube 3-5having a flanged head 36 on its upper end. Tube 35 is secured by a pressfit in a tube 37 so that the diaphragm is clamped between the upper endof tube 37 and flange 36. The lower end of tube 37 has an annular valvesurface 38 which seats on a resilient washer 39 supported on a shoulder40 in the lower end of body 25. A pilot extension 41 on the lower end oftube 37 projects through washer 39 to serve as a guide for tube 37 andprevent the tube from cocking in an inclined position. Tube 37 hasopenings 42 in the lower portion of its side wall and contains a floatvalve 43 which is adapted to seat against a resilient washer 44 at thelower end of tube 35.

The lower end of body 25 has an extension 50 for connection with pipe 16and this extension is provided with vacuum breaker or anti-syphoningopenings 51. A vertical air tube 52 has an angular fitting on its lowerend with a nipple 55 for connection with body 25 and communicationthrough a side passage 53 with the chamber 28.

When no water is being drawn in the building, the static water pressurein chamber 27 presses diaphragm 26 downward, holding valve surface 38seated against washer 39 to prevent any flow of water through thedevice, as shown in FIGURE 1. Tube 52 is full of water except for apocket of trapped air at its upper end which is compressed by the waterpressure. Chamber 28 and tube 37 are full of water with the float 43bearing lightly against the washer 44 by reason of the buoyancy of thefloat.

When a faucet or other valve is opened anywhere in the building allowingwater to flow, there is a reduction in pressure in branch pipe 17allowing diaphragm 26- to move upward to its FIGURE 2 position under thepressure exerted by the trapped air compressed in the upper end of tube52. It will be appreciated that any reduction in pressure on the upperside of the diaphragm will cause the float 43 to seat more firmlyagainst washer 44 as a check valve to prevent any equalization ofpressures through tube 35. Thus, the lifting of diaphragm 26 unseats thevalve surface 38 from washer 39 to allow equalizationof pressure byescape of a small amount of water through the washer and into dischargeconnection 50'.

This discharge of water allows the trapped air in the upper end of tube52 to expand until its pressure, exerted through chamber 28,isinsuflicient to hold the diaphragm deflected upward against thepressure in chamber 27. When this occurs, the diaphragm is againdeflected downward to its FIGURE 1 position, closing the valve surface38 against washer 39. Regardless of how long the reduction in pressuremay persist in pipe 17, no more water will be discharged into trap 11.The amount of water discharged into the trap varies with the pressuredrop in pipe 17 and is normally a spoonful or two. This small amountreleased many times a day more than compensates for evaporation lossfrom the trap but does not waste an appreciable amount of water. Thevalve 38 does i not remain open long enough for the entire contents ofchamber 28 and tube 52 to discharge.

When the opened faucet or valve has been closed, restoring normal staticpressure to chamber 27, the pressure on the upper side of the diaphragmbecomes momentarily higher than the pressure on the lower side. Thispressure differential unseats float valve 43 as shown in FIGURE 1 untilsufiicient water has flowed into tube 52 to compress the trapped air atthe top of the tube back to a volume where its pressure balances thepressure in chamber 27. Then float 43 reseats on washer 44 with a lightforce corresponding merely to the buoyancy of the float. The trapped airin the upper end of tube 52 remains there permanently. Valve 43 may bebiased to closed position by a light spring instead of buoyancy, ifdesired.

It will be observed that different effective areas of the diaphragm areexposed to the pressures in chamber 27 and 28, This permits thesensitiveness of the diaphragm to small pressure drops in pipe 17 to becontrolled by the choice of dimensions for the inside diameter of tube35 and the wall thicknesses of the two tubes 35 and 37. The device maythus be made as sensitive as desired to respond to very small pressuredrops in branch pipe 17. The trapped air in tube 52 provides the springpressure for raising the diaphragm and is automatically self-adjustingto changes in the water main pressure.

Float valve 43 permits complete draining of the system to preventfreezing in cold weather. When pressure in pipe 18 is reduced toatmospheric pressure, the water will run out of tube 52 and chamber 28.Water remaining in branch pipe 17 has insufiicient pressure to holdvalve 38 firmly seated whereby this water also will gradually leak awayto the drain trap 11. If desired, a nail may be inserted throughopenings 51 to lift the stem 41 and hold valve 38 open. Instead ofutilizing buoyancy to hold check valve 43 closed, a light spring may beemployed if desired.

FIGURE 3 shows a modification 15A having a piston 26a in place of thediaphragm 26. In all other respects, the construction and operation arethe same as described in connection with FIGURES land 2. The termdiaphragm in the appended claims includes a piston-type diaphragm aswell as a flexible-type diaphragm.

In some cases it may be found that there is a tendency for the trappedair in the top of tube 52 to dissolve in the water over a period of timeand reduce the effectiveness of the air spring. This is prevented inFIGURE 5 where the air chamber 56 is separated from water chamber 57 bya flexible diaphragm 60.

Also, if desired, a metal spring 61, inFIGURE 6, may be substituted forthe air spring in FIGURES 1 to 5. The metal spring performs the samefunction as the air 7 spring and is not objectionable as the metalsprings in conventional primer valves because it does not requirecalibration or adjustment. The spring chamber is vented to atmosphere at62 or a combination of air spring and metal spring may be employed byomitting the vent 62.

.means comprising an air The parts not shown in FIGURES 5 and 6 may bethe same as shown in FIGURE 2 or FIGURE 3.

The present valve in all of its modifications responds also to anypressure shock or water hammer in the out side main as well as gradualchanges in outside main pressure. This insures that the drains will bekept primed in an unoccupied building where the faucets are not beingpressure on said diaphragm'in said supply chamber to close said outlet,an opening between said two chambers,

a check valve in said opening permitting flow from said supply chamberto said dispensing chamber and preventing back flow, and resilient meansarranged to be compressed by the water pressure in said dispensingchamber and maintain pressure in said dispensing chamber to hex saiddiaphragm and open said outlet valve whenever the pressure is reduced insaid supply chamber.

2. A primer valve as defined in claim 1, said resilient means comprisinga trapped air chamber connected with said dispensing chamber. 7

3. A primer valve as defined in claim 1, said resilient chamber and aflexible diaphargm closing one side of said chamber, said diaphragmbeing exposed on one side to the Water pressure in said dispensingchamber to compress the air in said air chamber.

4. A primer valve as defined in claim 1, said resilient means comprisinga spring engaging one side of a flexible diaphragm, the opposite side ofsaid diaphragm being exposed to the water pressure in said dispensingchamber to compress said spring.

5. A primer valve comprising a pair of chambers sepa-' pair of chambers,and a check valve in said opening independent of said outlet valvepermitting flow from said first chamber to said second chamber andpreventing back flow.

6. A primer valve comprising a supply chamber and a dispensing chamberseparated by a diaphragm, an inlet connection in said supply chamber, anoutlet in said dispensing chamber, a valve operable by movement of saiddiaphragm under pressure in said supply chamber to close said outlet, atrapped air chamber connected with said dispensing chamber, an openingbetween said supply and dispensing chambers, and a check valve in saidope'ning independent of said outlet valve permitting flow from saidsupply chamber to said dispensing chamber and preventing back flow.

7. A primer valve comprising a supply chamber and a dispensing chamberseparated by a diaphragm, an inlet connection in said supply chamber, anoutlet in said dispensing chamber, a tubular member in said dispensingchamber connected with said diaphragm and having a valve portion toclose said outlet, an opening through said diaphragm into said tubularmember, an opening in said tubular member Within said dispensingchamber,:a float valve in said tubular member for said diaphragmopening, and an air chamber connected with said dispensing chamber andextending above said dispensing chamber.

S. A primer valve comprising a chambered body member having an open end,a chambered cap on said open end of said body member, a diaphragmseparating said two chambers, a water supply connection for said capchamber, an outlet in said body chamber having a valve seat, a tubularmember connected at one end to said diaphragm and having a valve on itsother end to cooperate with said seat, an opening in said tubular memberwithin said body chamber, an opening in said diaphragm having a valveseat Within said tubular member, a float valve in said tubular memberengageable with said last seat, and

an air chamber communicating at its lower end with said body chamber,

References Cited 5 UNITED STATES PATENTS 2,233,818 3/1941 Matter 137-l15 2,938,530 5/1960 Matter 137l15 WILLIAM F ODEA, Primal Examiner. 10 D.J. ZOBKIW, Assistant Examiner.

1. A PRIMER VALVE COMPRISING A SUPPLY CHAMBER AND A DISPENSING CHAMBERSEPARATED BY A FLEXIBLE DIAPHRAGM, A WATER INLET CONNECTION IN SAIDSUPPLY CHAMBER, AN OUTLET IN SAID DISPENSING CHAMBER, A VALVE OPERABLEBY PRESSURE ON SAID DIAPHRAGM IN SAID SUPPLY CHAMBER TO CLOSE SAIDOUTLET, AN OPENING BETWEEN SAID TWO CHAMBERS, A CHECK VALVE IN SAIDOPENING PERMITTING FLOW FROM SAID SUPPLY CHAMBER TO SAID DISPENSINGCHAMBER AND PREVENTING BACK FLOW, AND RESILIENT MEANS ARRANGED TO BECOMPRESSED BY THE WATER PRESSURE IN SAID DISPENSING CHAMBER AND MAINTIANPRESSURE IN SAID DISPENSING CHAMBER TO FLEX SAID DIAPHRAGM AND OPEN SAIDOUTLET VALVE WHENEVER THE PRESSURE IS REDUCED IN SAID SUPPLY CHAMBER.